Studies on the Physiological adaptations during Pregnancy and Lactation in Dwarf Goat to Improve its Production

Abstract

Physiological characteristics of an animal depend, mainly on the abilities to use nutrients, appropriately through regulation, for growth and reproduction. Their precise control for the need through mobilization, deposition etc. is dependent upon various hormones. An animal passing through varied reproductive phases has different demands for the nutrients accompanying altering hormonal setup for physiological adaptation. Some of these physiological characteristics are the indicator of economic benefits or disadvantageous in a breed. Therefore, adequate, understanding of physiological setup is the prerequisite for the biotechnological procedures to be considered in farming. The present project work is undertaken to fulfill this objective. Synchronization is the technique where a large number of female mammals, particularly, ruminants may be brought to cycle, ovulate, conceive and give birth nearly at the same time, thus rendering management economical , particularly, in technological farming. Prostaglandin synchronization, as understood in the present investigation, may be employed successfully in goats, however, it has been found to required planned artificial insemination and adversely affects the multiovulatory characteristic of the breed of the goat under study. It is also shown that synchronization of a cycle may continue in the subsequent cycles, therefore synchronization once employed could be exploited for several subsequent cycles and pregnancies through planned management. This approach maintains multiple birth characteristic of the goat and provide economical management in gestation, may be used as an indicator of multiple birth supplementations may be worked economically. Circulatory levels of least investigated non gonadal hormones, now understood important also in reproductive functions, were estimated through sensitive radioimmunoassay (RIA) methods. Similarly essential nutrients in the blood were observed corresponding to the hormones’ levels. The present study also comprised the investigations on some pertinent targets that include circulatory free amino acids and the protein fractions resolved by thin layer chromatography and sodium dodecyl sulfate polyacrylamide gel electrophores, respectively. It is rationalized that the interactions of the hormones that mobilize energy nutrients in the blood during cycle contribute in multiovulatory or high multiple birth rate in the breed. In the extensive study of the free amino acid profiles and their pattern in the cycling goat, it is understood that some fractions are specifically elevated and a few others are noticeably reduced in the estrus phase. Three protein fractions that particularly appeared in estrus may be indicated as the regulatory for the mobilization of energy nutrients or regulation of metabolism in multiovulatory characteristic of the breed. In early pregnancy, termed as the anabolic phase, the levels of the hormones and the associated nutrients are clearly diverted for storage. This interaction in the hormones and the nutrients are clearly diverted for storage. This interaction in the hormones and the nutrients in the later half of the pregnancy is reversed and because of the demands in the fetal growth, energy substrates are maximally diverted towards uterus. This investigation, in this dwarf breed, provides information regarding the statue of the hormones and the circulatory nutrients hat sustain multiple fetuses in the breed. A few fraction of free amino acids exceptionally remained enhanced in the entire gestation compare to pregnancy state. Their increased presence may be considered necessary for the gestational adaptation by the breed to carry multiple fetuses. Decline in the several protein fractions and appearance of a new signifies the role of these in anabolism of early pregnancy. Also the appearance of four new protein fractions in the late pregnancy may be attributed to the catabolic rate of these in late pregnancy. In lactation, the status of the studied hormones with the resultant target nutrients level in the blood shows that partitioning of the nutrients is not favorable for adequate let down of milk in this breed of the goat. It is realized that metabolic setup of the goat, adapted in pregnancy, fails to shift to an efficient lactational level. The restoration of the levels of certain free amino acids peculiar to pregnancy, soon after a short early lactation, in mid lactation supports this apprehension. Also the appearance of a protein very specific to the cycling characteristic of the goat in early lactation demonstrates that the physiological set up of the goat is soon onset to subsequent cycling. This renders the lactation phase poor in performance. It is suggested from the findings that this breed of goat may be utilized for extensive breeding due to early cycling post parturition, however, with technological care of the kids instead of depending upon the nanny goats. The enhancing of let down milk in Dwarf goat may be possible by exogenous administrations of related factors, however, it requires a separate planned study.